The number of deaths linked to so-called legal highs could overtake those linked to heroin by 2016, a think tank has warned.

In a new study, the Centre for Social Justice says the rise of legal highs was linked to 97 deaths in 2012 and hospital admissions soared by 56% between 2009-12.

It forecasts that on current trends deaths related to legal highs could be higher than heroin by 2016 - at around 400 deaths per year.

It adds that despite small reductions in the number of people using heroin and those drinking every week, the costs of addiction are rising with alcohol-related admissions to hospital doubling in a decade.

Researchers say residential treatment - the most effective form of abstinence-based treatment - has been continually cut and are calling for this to be reversed.

The think tank, which has influenced many of the coalition's social policy programmes, is calling for a "treatment tax" on all alcohol sales to fund a new generation of rehab centres for alcohol and drug addicts.

Under the scheme, a levy of a penny per unit would be added by the end of the next Parliament to fund recovery services to the tune of £1.1bn over the five years.

Image Caption:The Centre for Social Justice wants a 'treatment tax' on alcohol sales

"For years full recovery has been the preserve of the wealthy - closed off to the poorest people and to those with problems who need to rely on a public system. We want to break this injustice wide open."

Video:Crackdown On Legal Highs

The report says 300,000 people in England are addicted to opiates and/or crack, 1.6 million are dependent on alcohol and one in seven children under the age of one live with a substance-abusing parent.

Every year drugs cost society around £15bn and alcohol £21bn, the report adds.

Meanwhile, three revellers at the V Festival in Staffordshire have been treated for "serious side-effects" after taking tablets called "Blue Ghost" that they thought was ecstasy.

Police said on Saturday night: "Emergency teams have treated people this evening who took a blue tablet they believed to be ecstasy at V Festival in Weston Park.

"All had serious side-effects after taking the tablets and needed urgent medical treatment."

It is believed the trio reported stomach problems, though none required hospital treatment.